Various kinds of safety helmets such as for example motorcycle helmets, bicycle helmets, helmets which are worn by pilots, safety helmets or hard hats which are worn on building sites and safety helmets for tank drivers are known. The function of those helmets is in particular to protect the heads of their wearers from blows and accidents. In the general situation such helmets are used in an environment in which, besides an increased risk of blows, there is also an increased level of noise or interfering background sound. In such environments background noise suppression, particularly to protect a helmet wearer from interfering background noise, and also the interference-free use of communication means, in particular communication means for listening or talking, represents a technical challenge.
U.S. Pat. No. 6,683,965 B1 discloses an in-the-ear earphone for noise reduction. Disposed on the earphone is a cushion with a cavity, that is arranged in the ear of a user. Disposed in the cavity are a loudspeaker and a microphone which is mounted to the loudspeaker. That headphone structure is then used for noise reduction.